Offset.prototype.margin = function(dist) {
var offsetEdges = [],
vertices = [],
i, len, union;
for (i = 0, len = this.edges.length; i < len; i++) {
var edge = this.edges[i],
dx = edge._inNormal[0] * dist,
dy = edge._inNormal[1] * dist;
offsetEdges.push(edge.offset(dx, dy));
}
for (i = 0, len = offsetEdges.length; i < len; i++) {
var thisEdge = offsetEdges[i],
prevEdge = offsetEdges[(i + len - 1) % len],
vertex = intersection(
prevEdge.current,
prevEdge.next,
thisEdge.current,
thisEdge.next
);
if (vertex) {
vertices.push(vertex);
} else {
this.createArc(
vertices,
this.edges[i].current,
dist,
prevEdge.next,
thisEdge.current,
this._arcSegments,
true
);
}
}
union = GreinerHormann.union(vertices, vertices);
if (union) {
union = union[0];
// that's the toll
vertices = union.slice(0, union.length / 2);
}
vertices = this.ensureLastPoint(vertices);
return vertices;
};
Offset.prototype.padding = function(dist) {
var offsetEdges = [],
vertices = [],
i, len, union;
for (i = 0, len = this.edges.length; i < len; i++) {
var edge = this.edges[i],
dx = edge._outNormal[0] * dist,
dy = edge._outNormal[1] * dist;
offsetEdges.push(edge.offset(dx, dy));
}
for (i = 0, len = offsetEdges.length; i < len; i++) {
var thisEdge = offsetEdges[i],
prevEdge = offsetEdges[(i + len - 1) % len],
vertex = intersection(
prevEdge.current,
prevEdge.next,
thisEdge.current,
thisEdge.next);
if (vertex)
vertices.push(vertex);
else {
this.createArc(
vertices,
this.edges[i].current,
dist,
prevEdge.next,
thisEdge.current,
this._arcSegments,
false);
}
}
union = GreinerHormann.union(vertices, vertices);
vertices = union ? union[0] : vertices;
vertices = this.ensureLastPoint(vertices);
return vertices;
};